/// <summary>
/// Merges two lists of ValueChange objects, canceling out any matching Add/Delete pairs and duplicate values
/// </summary>
/// <param name="attribute">The attribute that the ValueChanges represent</param>
/// <param name="sourceList">The original list of ValueChanges</param>
/// <param name="newValues">The new list of ValueChanges</param>
/// <returns>A new list containing the merged values from both lists</returns>
public static IList <ValueChange> MergeValueChangeLists(AcmaSchemaAttribute attribute, IList <ValueChange> sourceList, IList <ValueChange> newValues)
{
IList <ValueChange> newList = new List <ValueChange>(sourceList);
if (newValues.Count == 0)
{
return(newList);
}
ValueChangeComparer valueComparer = new ValueChangeComparer(attribute, false);
IList <ValueChange> nonDuplicatedNewList = RemoveDuplicateValueChanges(attribute, newValues);
foreach (var newChange in nonDuplicatedNewList)
{
ValueChange changeInSource = sourceList.FirstOrDefault(t => valueComparer.Equals(newChange, t));
if (changeInSource == null)
{
newList.Add(newChange);
}
else
{
if (changeInSource.ModificationType == ValueModificationType.Add)
{
if (newChange.ModificationType == ValueModificationType.Delete)
{
Logger.WriteLine("Canceled attribute add due to subsequent delete: {0} - {1}", LogLevel.Debug, attribute.Name, changeInSource.Value.ToSmartStringOrNull());
newList.Remove(changeInSource);
}
else if (newChange.ModificationType == ValueModificationType.Add)
{
Logger.WriteLine("Duplicate add detected: {0} - {1}", LogLevel.Debug, attribute.Name, changeInSource.Value.ToSmartStringOrNull());
continue;
}
}
else if (changeInSource.ModificationType == ValueModificationType.Delete)
{
if (newChange.ModificationType == ValueModificationType.Add)
{
Logger.WriteLine("Canceled attribute delete due to subsequent add: {0} - {1}", LogLevel.Debug, attribute.Name, changeInSource.Value.ToSmartStringOrNull());
newList.Remove(changeInSource);
newList.Add(newChange);
}
else if (newChange.ModificationType == ValueModificationType.Delete)
{
Logger.WriteLine("Duplicate delete detected: {0} - {1}", LogLevel.Debug, attribute.Name, changeInSource.Value.ToSmartStringOrNull());
continue;
}
}
}
}
return(newList);
}
public static IList <ValueChange> RemoveDuplicateValueChanges(AcmaSchemaAttribute attribute, IList <ValueChange> changes)
{
ValueChangeComparer changeComparer = new ValueChangeComparer(attribute, true);
return(changes.Distinct(changeComparer).ToList());
}
